Additional settings-related features and issues within Microsoft Teams for business
I'm having the same issue reported here, and there are no settings in Editor spellcheck.
Clicking manage I go to a screen with no languages, and if I add one and then go back, it still keeps showing no options to disable spell correction.
It is really a mess to work with when everything has a recommendation to fix because it's checking another language.
Just updated and running 26106.1911.4707.3286.